Are Genetically Modified Organisms (GMO) Safe For Humans?

Much controversy surrounds the creation and use of GMOs in food, pharmaceuticals, human gene therapy, and other fields.

We hear a lot about GMOs in the media, but what does science tell us about their safety?

What Is A GMO?

A GMO, or a genetically modified organism, refers to an organism whose genetic material has been modified by genetic engineering procedures in a laboratory environment. The Cartagena Protocol on Biosafety defines GMOs as being "any living organism that possesses a novel combination of genetic material obtained through the use of modern biotechnology”. Those GMOs whose genetic material has been altered by introducing the genetic material from another organism are known as "transgenic" organisms. Since the genes of an organism determine its phenotype (physical appearance and characteristics), altering the genetic material alters the phenotype of the organism, which then exhibits new traits which it was not naturally seen to exhibit.

Historical Role and Pioneers In The Field

The concept of the genetic modification of organisms was preceded by the practice of selective breeding by humans carried out for thousands of years. In selective breeding, also known as "artificial selection", humans select only those species of plants or animals that possess a favorable trait, and breed two such animals (or cross-pollinate such plants) together to produce offspring that possess the desired characters of their parents. In this way, farmers and livestock grazers have developed plants and animals that provide them with the greatest benefits. With the development of recombinant DNA technology in the 20th Century, selective breeding gave way to the production of GMOs, wherein, instead of resorting to the long process of breeding animals for selective traits, an organism’s genetic material itself is altered in the laboratory, and then the organism is cloned to produce several identical copies which are then propagated in a natural manner.

After the creation of the first recombinant DNA in 1972 by American Paul Berg, two other American scientists, Stanley Cohen and Herbert Boyer, created the first GMO in 1973. The same year witnessed another major advancement in the field of biotechnology when German-born U.S. researcher Rudolf Jaenisch created the first transgenic mouse. Another team of three brilliant scientists, Michael W. Bevan and Richard B. Flavell of the United Kingdom and Mary-Dell Chilton of the United States, created the first transgenic plant. Soon, several genetic technologies, methods, and devices were developed, and each of these successive advances made the process of genetic engineering increasingly more efficient. The first genetic engineering company, Genentech, was established in the U.S. in 1976 and headquartered in South San Francisco, California, and started producing the genetically engineered "humulin", or human insulin, in 1978. In 1994, the first genetically modified food, the Flavr Savr tomatoes, were released into the market for consumption after FDA approval. In the years that followed, several other drought-, disease-, and pest-resistant varieties of plants were developed. In 2010, the first human-engineered synthetic bacterial genome was produced by scientists of the J. Craig Venter Institute. In 2015, AquAdvantage salmon became the first genetically modified animal to be approved for use as food.

Practical Applications

Plants which have been genetically engineered usually exhibit greater crop yields per acre of land per year, and also require decreased use of chemicals like insecticides and pesticides for their protection. For example, "Bt cotton" is a genetically engineered cotton variety which possesses a gene from the bacteria Bacillus thuringiensis and produces a toxin deadly to insect pests, the Bt toxin, by virtue of this gene. The introduction of Bt cotton in India led to a dramatic reduction in bollworm infestations of cotton, leading to 30% to 80% higher yields. Herbicide-resistant crop plants have also been produced by genetic engineering which are unaffected by the use of the herbicides used to eliminate weeds in crop fields. Crop plants have also been genetically modified to produce desired food qualities, such as "golden rice" which produces high amounts of the nutrient beta carotene to help overcome Vitamin A deficiencies. GM crops that are resistant to drought conditions have also been developed by scientists. GMOs find widespread applications in biomedical research as well, where by tweaking the genes in organisms scientists may better be able to understand the role of these genes in the human body. The GMOs are also used for mass scale production of vaccines and other pharmaceuticals, such as the production of human insulin from genetically engineered bacteria, and the recombinant Hepatitis B vaccine from genetically modified Baker’s yeast.

Controversy and Safety

Up to the present date, though the GMOs appear to have a promising future, a lot of controversy surrounds the use of GMOs, especially those used as human food. The best argument provided by several non-governmental organizations like Greenpeace, the Organic Consumers Association, and the Union of Concerned Scientists is that, though GMOs are greatly benefiting the human population currently, sufficient evidence regarding the long term effects of these GMOs on human health and the natural environment is absent. They also claim that GMOs might adversely affect the non-GMOs as accidental cross-breeding between the GMOs and non-GMOs might result in generating organisms with completely new set of genes and characteristics. This prospective phenomenon has come to be known as "genetic pollution". There is also a huge debate concerning whether GMOs ought to be labelled as such or not in the marketplace. In the United States, foods that are derived from GMOs are not specifically labelled. It is also possible that the labeling of GMOs might influence the public to select non-GMO-based foods over GMO-based ones. However, the goal of solving the global scarcity of food by the high-yielding GMO-based crops would then become difficult to achieve.

Recent Developments and Future Research

By 2010, over 10 million square kilometers of area of land in the world were dedicated to the growth of GM crops. In the United States, by 2014-15 around 90% of the cotton, soybeans, and corn grown in the country were GM. Vigorous research is being conducted today to rapidly develop GMOs with newer traits and enhanced properties. Recombinant plants are being developed that could act like edible vaccines and will serve as a painless, effortless, and low-cost vaccination methods, solving the problem of limited refrigeration and sterile syringe availability in less developed countries. Genetically engineered mosquitoes are also being developed that can block the entry of the malarial parasite into them. The release of such GM mosquitoes into the wild could possibly help solve the health crises caused by malaria. The use of GMOs to produce biodegradable plastic is also another area of innovative research which holds promise to help save our fragile environment. GMOs might also be used in bioremediation techniques, where they can be designed to metabolize oil and heavy metals. Thus, the future prospects of GMOs are extremely high. However, it is also important that responsible research practices are adopted during the development and release of GMOs to avoid any uncontrollable catastrophes.